Look back. Try to remember all the actions that cause you regret. Analyze them why you did so, and not otherwise. Most likely, you will find good arguments to justify your actions. For example, are you sorry you chose the wrong profession he wanted. Every day, going to work, you torment yourself with the thought, I made a mistake and have to do unloved business. Remember why you decided to enroll in another school: due to excessive competition, which still have not been able to pass, or from the fact that, while in desired high school, you would not have the opportunity to earn and help the family? Accept your decision and stop beating yourself up, better focus on the advantages of your present job.
If possible, try to correct their actions. This act, whatever the consequences, he didn't turn, will help to remove the heaviness of regret and will push you to action. Ask for forgiveness from someone you have wronged, admit your feelings to the beloved one, etc. So you complete a certain Chapter of his life and no longer dwell on it.
Unfortunately, also caused by negative emotions, can have a positive impact. Remember their actions and firmly bind them in memory with this feeling. In the future, when you want to do the same thought about this action will cause a deep sense of regret, which no doubt will be back after done.
Psychologists believe that regret is more typical for the maximalists – those people who are all striving to achieve the ideal. That is why they are often thinking to myself what would have happened had they done otherwise. So people need to accept the fact that made back, but be sure to save this experience for the future.